Historically, postage meters have been mechanical and electromechanical devices that: maintain, through mechanical or "electronic registers" (postal security devices), an account of all postage printed and the remaining balance of prepaid postage; and print postage postmarks (indicia) that are accepted by the postal service as evidence of the prepayment of postage.
Soon, small business mailers may be able to use their desktop computers and printers to apply postage directly onto envelopes or labels while at the same time applying an address. The United States Postal Service Engineering Center recently published a notice of proposed specification that may accomplish the foregoing. The title of the specification is Information Based Indicia Program Postal Security Device Specification, dated Jun. 13, 1996, herein incorporated by reference. The Information Based Indicia Program specification includes both proposed specifications for the new indicium and proposed specifications for a postal security device (PSD). The proposed Information Based Indicia (IBI) consists of a two dimensional bar code containing hundreds of bytes of information about the mail piece and certain human-readable information. The indicium includes a digital signature to preclude the forgery of indicia by unauthorized parties. The postal security device is a security device that produces a cryptographic digital signature for the indicium and performs the function of postage meter registers.
One of the disadvantages of the prior art is that the IBI can be reused if the mail piece is returned to the sender and sent back to the same recipient addressee. An example of a way in which the IBI can be reused is as follows. Mailer A addresses envelope #1 to recipient B. Recipient B receives envelope #1 from mailer A and addresses envelope #2 to original mailer A and places in envelope #2 in the original envelope #1 sent to recipient B. Mailer A receives envelope #2 from recipient B. Mailer A then places envelope #2 sent to him by B in the original envelope #1 used by mailer A and resends envelope #1 and its contents to recipient B without the payment of any additional postage. Recipient B can then use the envelope #2 he previously sent to Recipient A without the payment of any additional postage. The above procedure may be continued many times without the payment of additional postage. The IBI affixed to the mail piece will contain in the IBI an indication of the address of recipient B.
The prior art included a system that indicated when normal digital postage meter mail or PSD mail was received by an addressee. The foregoing was accomplished by connecting a scanner and control software to a digital postage meter or PSD mail processor that would read incoming digitally metered mail. Instead of printing an indicia, the scanner would read the already existing indicia and other information on the mail piece and then extract the sender data fields that are contained in the indicia or on the mail piece. The extracted mail data would be periodically uploaded to a data center. The data center would compare the extracted data with mail sender data that has previously been uploaded from sending meters and processors to determine the delivery time of particular mail pieces.
Although the forgoing worked well for its intended purpose, another problem of the prior art is that it did not take into account human error caused by people feeding into the scanner mail pieces that were already scanned and read. In essence, someone just had the scanner rescan mail pieces that have already been scanned. The probability of the forgoing happening is increased if there is more than one person in the mail room and there are different shifts.